Open Paleo

Bagaceratops

Maryańska & Osmólska, 1975 BAH-gah-SER-a-tops

From Mongolian baga meaning 'small' + Greek keras (κέρας) meaning 'horn' + ops (ὤψ) meaning 'face'; overall meaning 'small-horned face'.

83.6–72.2 million years ago Campanian, Late Cretaceous
Late Cretaceous stages

Bagaceratops is a genus of small protoceratopsid dinosaurs that lived in Asia during the Late Cretaceous, around 72 to 71 million years ago. Bagaceratops remains have been reported from the Baruungoyot Formation and Bayan Mandahu Formation. One specimen may argue the possible presence of Bagaceratops in the Djadokhta Formation.

Diagnosis

  1. Parietosquamosal frill short, most probably without fenestrae
  2. Nasals bearing a prominent unpaired horn core
  3. Additional antorbital fenestra present, located at the premaxilla-maxilla suture
  4. Premaxillary dentition absent; anterior edentulous portion of upper jaw very long
  5. Mandible shallow with straight ventral margin
  6. Ten maxillary teeth in largest known specimen

Species

Bagaceratops rozhdestvenskyi Maryańska & Osmólska, 1975

Type species

Named for Russian paleontologist Anatoly Konstantinovich Rozhdestvensky for notable work on dinosaurs.

Holotype
ZPAL MgD-I/126 , Institute of Paleobiology, Polish Academy of Sciences
Material
Nearly complete skull with mandible, lacking anterior portion of snout.
Horizon
Baruungoyot Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
Hermiin Tsav, Ömnögovi, Mongolia

Synonyms

  • Gobiceratops junior subjective

    G. minutus is now interpreted as a growth stage or individual variant of Bagaceratops rozhdestvenskyi (Makovicky 2006; Czepiński 2019).

  • Lamaceratops junior subjective

    L. tereschenkoi is now interpreted as a growth stage or individual variant of Bagaceratops rozhdestvenskyi (Makovicky 2006; Czepiński 2019).

  • Magnirostris junior subjective

    M. dodsoni is now interpreted as a growth stage or individual variant of Bagaceratops rozhdestvenskyi (Makovicky 2006; Czepiński 2019).

  • Platyceratops junior subjective

    P. tatarinovi is now interpreted as a growth stage or individual variant of Bagaceratops rozhdestvenskyi (Makovicky 2006; Czepiński 2019).

Notable specimens

  • MPC-D 100/535

    Paleontological Center, Mongolian Academy of Sciences Found 1993 by Japan-Mongolia Joint Paleontological Expedition pathology

    Examined in 2010-2011 for tunnel-like borings left by invertebrate scavengers on its joint surfaces, a notable record of post-mortem invertebrate scavenging. The articulated, nearly complete skeleton from Hermiin Tsav otherwise remained largely undescribed as of 2019.

    Matsumoto & Saneyoshi (2010)

References

  1. Maryańska, T.; Osmólska, H. (1975). Protoceratopsidae (Dinosauria) of Asia. Palaeontologia Polonica 33: 133-182. maryańska1975a
  2. Matsumoto, Y.; Saneyoshi, M. (2010). Bored dinosaur skeletons. The Journal of the Geological Society of Japan 116(1): I-II. doi:10.5575/geosoc.116.1.I_II matsumoto2010a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Ornithischians. Princeton University Press.

    Source of the hip height estimate, and the appearance features.

    jones2026a
  4. Makovicky, P. J.; Norell, M. A. (2006). Yamaceratops dorngobiensis, a New Primitive Ceratopsian (Dinosauria: Ornithischia) from the Cretaceous of Mongolia. American Museum Novitates 3530: 1-42. American Museum of Natural History (BioOne sponsored). doi:10.1206/0003-0082(2006)3530[1:ydanpc]2.0.co;2

    Interpreted the referred species tatarinovi as a growth stage of Bagaceratops rozhdestvenskyi.

    makovicky2006a
  5. Czepiński, Ł. (2019). Ontogeny and variation of a protoceratopsid dinosaur Bagaceratops rozhdestvenskyi from the Late Cretaceous of the Gobi Desert. Historical Biology 32: 1394-1421. doi:10.1080/08912963.2019.1593404 czepiński2019a